Activators of Yeast Hexokinase

Activators of yeast hexokinase.

The rate of the ATP:glucose transphosphorylase reaction catalyzed by yeast hexokinase, isozyme PII, is inhibited by lowering the pH of the reaction below 7.0, especially at suboptimal concentrations of ATP. This effect of acidity is largely overcome by activators such as orthophosphate, citrate, malate, 3-phosphoglycerate, and riboside triphosphates. Thus, in the acid range, ATP appears to serv...

Inhibitors and activators of brain hexokinase.

Activation of Yeast Hexokinase PI1

Activation of yeast hexokinase PI1 at low pH by citrate or ATP has been shown to occur at the monomer level, without requiring association to the dimer level. Thus, the previous suggestion (Steitz, T. A., Anderson, W. F., Fletterick, R. G., and Anderson, C. M. (1977) J. Biol. Chem. 252, 4494-4500) that anionic activators of hexokinase, such as citrate and ATP, act by binding to the intersubunit...

Kinetic studies of yeast hexokinase.

The mechanism of calf brain hexokinase has recently been studied in our laboratory (1). It was concluded from kinetic experiments that adenosine diphosphate (ADP) dissociates from the enzyme before addition of substrate glucose. This hypothesis was supported by kinetic studies of n-mannose, ADP, and glucose g-phosphate inhibition. The experiments appear to lend credence to theories in which an ...

Transcriptional activators in yeast

Eukaryotic transcription activation domains (ADs) are not well defined on the proteome scale. We systematicallly tested approximately 6000 yeast proteins for transcriptional activity using a yeast one-hybrid system and identified 451 transcriptional activators. We then determined their transcription activation strength using fusions to the Gal4 DNA-binding domain and a His3 reporter gene which ...